This invention relates to a printing plate, according to which a silver image obtained by the silver complex diffusion transfer process which is one of the photographic reproduction methods can be directly used as an offset printing plate and to an improvement in direct offset printing plates for negative originals disclosed in Japanese Patent Publication No. 30562/73.
Japanese Patent Publication No. 30562/73 and Japanese Patent Laid-Open Application No. 55402/74 disclose direct offset printing plates for positive originals in detail. In order to obtain direct offset printing plates for negative originals it can be considered to use a direct-positive silver halide emulsion. The emulsion layer influences printabilities such as ink receptivity, water retention, plate strength, etc. and the conditions for obtaining direct offset printing plate for negative originals which satisfy said printabilities have never been clarified.